The recent emphasis on both environmental protection and energy conservation has caused a significant increase in both the popularity and importance of solar energy systems, especially since radiant solar energy constitutes an enormous energy source which is relatively untapped by today's standards and which can be utilized without the undesirable environmental side effects occurring in the production of energy through the burning of conventional fuel sources.
One typical solar energy collector system employs reflector means to concentrate beam energy (i.e. direct rays of solar radiation) upon fluid carrying means positioned at the focal point of the reflector. These systems have the drawback of generally requiring the capability of tracking the sun, necessarily increasing the cost of such systems and further having the disadvantage of significantly reducing efficiency of the energy absorbed as a result of overcast or cloudy conditions which serve to convert beam energy into diffuse energy (i.e. radiation which consists of randomly distributed rays) which are incapable of being reflected and concentrated upon the fluid carrying element.
Another general type of solar energy collector is the solar panel which is comprised of a metallic panel or sheet adapted to absorb radiation from the sun's rays in the form of beam and/or diffuse energy. Fluid carrying tubes are positioned beneath the panel and by means of conduction, the heat energy absorbed by the panel is conducted to the tubes and transferred to the fluid carried therethrough, which fluids are then directed to a utilization means in the form of a hot water tank, swimming pool, hot water heating system and the like.
Solar panel type energy collectors suffer from the disadvantages of continually changing efficiency as the sun changes its position relative to the earth, which may be remedied by expensive tracking means; and large heat losses (i.e. high emissivity) due to the large surface area of the absorptive panel. Also, convection losses further serve to reduce the efficiency of panel type solar collectors.